Twin-blade releasing means



Feb. 15, 1966 H. PREBLE ETAL 3,234,649

TWIN-BLADE RELEASING MEANS Filed March 13, 1964 I'll INVENTORS.

H/ Hurry Preble 8 BY 2 Joseph Rubinstein,

ATTORNEY,

United States Patent ()fiice 3,234,649 Patented Feb. 15, 1966 3,234,649 TWIN-BLADE RELEASING MEANS Harry Preble, Cross River, and Joseph Rubinstein, Newburgh, N.Y., assignors to General Slicing Machine Co. line, Walden, N.Y., a corporation of New York Filed Mar. 13, 1964, Ser. No. 351,698 7 Claims. (Cl. 30-272) The present invention relates to power-driven hand knives in which two cutting blades in face-toface contact, reciprocate with a comparatively short stroke longitudinally in opposite directions. More particularly, this invention is concerned with constructions affording easy removal of said blades so that they can be cleaned, sharpened and replaced as becomes necessary.

An object of this invention is to provide novel and improved knives of the character mentioned, in which the blades are removed by the manipulation of but a single element movably mounted on the handle which is a casing having mechanism housed therein to actuate the cutting blades and same may include an electric motor or the like to furnish the driving power.

Another object thereof is to provide novel and improved blade-releasing means by which both blades are simultaneously released for removal though they are in overlapping relation, for it is only by accident that the blades shall be in fully superimposed relation when they come to rest.

A further object thereof is to provide novel and improved knife constructions of the type described, affording simple and inexpensive means to easily accomplish the removal and resetting of the blades, which are effective in action and efficient in carrying out the purposes for which they are designed.

Other objects and advantages will become apparent as this disclosure proceeds.

For one practice of this invention, there is some form of cut-out, as a notch or a hole in the end portion of each blade in the part thereof which is inside the handle and on each of the handle-housed slides supporting a, blade end located thereagainst, there is secured a blade spring which normally extends into and is engaged in said cut-out thereby securely holding the blade to its slide. An exposed movable element on the handle, is adapted when shifted, to act as a cam to bend both blade springs so that they come out of engagement from the respective cut-outs whereby the blades are leased for removal. In various embodiments herein shown, the two blade springs themselves are engaged in such manner that upon the movement of one by the release cam element, the other will also be moved to release position though not yet reached by such cam. This action accomplishes simultaneous release of both blades.

A more detailed description will now be given of various embodiments of this invention for which reference will be had to the acompanying drawing forming part of this specification, in which drawing, similar characters of reference indicate corresponding parts in all the views.

FIG. 1 is a fragmentary perspective view of a powerdriven, double blade hand knife embodying teachings of this invention.

FIG. 2 is a fragmentary face view of a blade provided with a notch to be engaged by a blade spring.

FIGS. 3, 4 and 5 are perspective views, each showing a difierent construction of related blade springs to engage the notches of the blades.

FIG. 6 is a perspective view of the blade-release element.

FIG. 7 is an enlarged section taken at line 77 in FIG. 1. Here the blade springs are those of FIG. 5.

FIG. 8 is an enlarged section taken at line 8-8 in FIG. 1. Here the blade springs are of a different type.

FIG. 9 is a perspective view of the blade springs employed in FIG. 8.

FIG. 10 is a perspective view of the release element used in FIG. 8.

FIG. 11 is a fragmentary face view of the blade of the kind used in FIG. 8.

In the drawing the numeral 15 designates generally an electric hand knife of the type having two cutting blades 16 and 17 in 'face-to-face-relation, mounted for longitudinal movement only, on the respective guided slides 18, 19 which are made to reciprocate in opposite directions by any suitable means which may be for instance by a crankshaft having its 180 degree-apart crank pins 20, 21 extend through the transverse slots 22, 23 in said slides respectively. These crank pins extend, one from each of the journalled hubs 24, 25 of a Worm wheel 26 which is meshed with a worm 27 fixed on the shaft of the electric motor 28. The operation of this motor is controlled by a normally open switch means indicated generally by the numeral 29, made to close by pressing on the springbiased bar 30 which is accessible on the handle 31; said handle being hollow and serving as the housing for said motor, crankshaft and slides. The cutting blades are of course partly within said handle. Each slide 18, 19 carries a form of cantilever blade spring detent for releasable engagement in an opening in the cutting blade associated therewith.

For the several forms of detents which are generally indicated by the numerals 32, 32, 33, 33', 34, 34, each has a notch as 35 to enter in the associated cutting blade. For the detents of the form indicated generally by the numerals 36, 36, each of the cutting blades has a hole as indicated at 37. FIG. 8 shows the use of the detent forms 36, 36', while FIG. 7 shows the use of the detents 34, 34. In all instances, the blade springs of the detent structures extend along the slides and hence along the handle, in one direction from their respective points of attachment to said slides, so that both detents of the knife are shiftable to release position by the manual movement of a single element which is a cam piece accessible on the handle. The various embodiments of these knife mounting and release means will now be described in detail.

The slides 18 and 19 are a right and left pair, and so are the pair of detents 34, 34; each of the latter comprising a blade spring having a downward tab as 37' at one end, for attachment to the blade it is on by a screw or rivet 38. The blade springs of these detents are along the top edges 'of the respective slides and their downward tabs 33, 39 are normally in position to engage the notches as 35 in the respectively associated cutting blades. Each of these detents may have an upwardly forwardly inclined tab as those shown at 40, 40' to cooperate with the cam fingers 41, 41' extending from a slide denoted generally by the numeral 42. This slide is slidably mounted on the handle 31 and is biased by a compression coil spring 43 to normally be in a position away from said detents 34, 34. Upon movement of this slide 42 towards said detents, their cam fingers will respectively engage the cam tabs 40, 40 and thus raise the detents which will upon such movement leave the notches in the blades and release them for removal from the handle 31 to be cleaned or sharpened. The end of each cutting blade is bevelled as shown at 45, so that upon insertion of the blade into the handle said bevel will cam the tab as 39 to raise, and then upon further inward movement of the blade, said tab will enter the notch in the blade to secure the blade against longitudinal movement with respect to the slide 18.

Since it is seldom that the slides 13, 19 will come to a common plane when the motor 28 stops, one will usually be ahead of the other and hence one of the cam fingers 41, 41' will raise its associated detent before the other cam finger does. So, with the use'of detents as 34, 34, the cutting blades 16, 17 will be successively released upon movement of the slide 42 by the hand of the operator.

In order that the blades 16, 17 shall simultaneously be released, the detents 32, 32' or 33, 33 are provided; such detents being of the same construction as the detents 34, 34' or substantially so, except that the lateral tabs which engage the respective cutting blades 16, 1'7, themselves engage so that upon the movement of one, the other will also likewise move. To accomplish such purpose, the detent 32 has a laterally extending finger 46 which extends into, is engaged by and is slidable in the slot of the detent 32, along such slot. Or as another embodiment for such purpose, the detent 33' has a laterally extending tab 48 which extends into the lengthwise slot 49 in the detent 33 and the latter detent has a laterally extending tab 51) which extends into the lengthwise slot 51 of the detent 33'. Said tabs 48 and t) are in contact and the tab 48 contacts the edge 49' of the slot 49. It is evident that the detents 32, 32. will move together upon the movement by the cam means of either one of them, and so will the detents 33, 33.

The detents 36, 36' have their blade springs along the faces of the cutting blades respectively and they are secured to the slides 18, 19 respectively by the rivets 52 to extend towards the tip end of said blades 16, 17. They are suitably bent as shown so that they are normally biased for their laterally extending pins 53, 53' shall be respectively entered in the holes, one of which is shown at 37, so that cutting blades 16, 17 are respectively engaged by such pins and thus held against longitudinal movement with respect to the slides they are on; Here, the releasing cam 54 of the slide 55 when the latter is moved towards said detents, will cooperate with the fingers 56, 56' to spread the detents 36, 36 apart and thus their pins 53, 53' will leave the holes in the cutting blades and thus said blades 16, 17 will be released for removal from the handle 31.

This invention is capable of numerous forms and various applications without departing from the essential features herein disclosed. It is therefore intended and desired that the embodiments shown herein shall be deemed merely illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific showings and description herein to indicate the scope of this invention.

We claim:

1. In a power-driven knife having two cutting blades in face-to-face relation extending from a handle and movable in relation thereto longitudinally, two opposite slides mounted in said handle for sliding movement therein along the length of said blades; said blades being mounted on said slides for longitudinal sliding movement therealong respectively and separable therefrom and from the handle by longitudinal movement; each of said blades having an opening in the region of its related slide, springbiased detents fixed on said slides respectively and in normal positions thereof, releasably engaging said blades in said openings respectively securely holding said blades on said slides against relative longitudinal movement with said slides respectively, means to reciprocate said slides for movement in opposite directions; both detents requiring a movement in one direction to shift them out of engagement from said openings to release said blades for removal from said slides and handle and a single cam-carrying element including cam means movably mounted longitudinally on the handle from a normal rest position to an operative position engaging said detents and moving same in said one direction by said cam means and upon return of said element to its normal rest position, allowing said detents to return to blade-engagement position.

2. A power-driven knife as defined in claim 1, including operative means on said detents connecting said detents together, adapted upon movement of said cam-carrying element to release the detents from their engagements with the respective cutting blades, that upon the movement of one of said detents by the cam means, the other detent will move with such moved detent before said other detent is moved by said cam means.

3. A power-driven knife as defined in claim 1, wherein the opening in each of the blades is a notch in a longitudinal edge thereof; such notches being in corresponding edges of said blades; each of said detents including a blade spring secured at one end to one of said slides and facing a longitudinal edge of the slide it is on; each detent having a laterally extending element; said lateral elements being engaged in said openings respectively and both said blade springs extending towards the cam means.

4. A power-driven knife as defined in claim 3, wherein each of the blade springs is provided with a lengthwise slot on a lateral extension therealong provided with a tab extending parallel to the blade spring it is on; the tab on each detent extending into the slot in the other, whereby on movement by the cam means of one of said detents, the other will move along with such moved detent before said other detent is moved by said cam means.

5. A power-driven knife as defined in claim 3, wherein each of the blade springs is provided with a lengthwise lateral extension therealong; one of said extensions having a slot therealong and the other having a finger extending into said slot and engaged thereby whereby on movement by the cam means of one of said detents, the other will move along with such moved detent.

6. A power-driven knife as defined in claim 3, wherein each cutting blade has that edge thereof which is notched, formed at its inner end in a manner so that it will act as a cam to shift its related detent upon being entered into the handle, whereby each blade can be so inserted and thereupon its detent will return into the notch in such entered cutting blade.

7. A power-driven knife as defined in claim 1, wherein, the opening in each cutting blade is a hole in the region of its slide; each of said detents including a blade spring secured at one end to one of said slides and facing the blade; each blade spring having a laterally extending element; said lateral elements being engaged in said holes respectively and both said blade springs extending towards the cam-carrying element.

References Cited by the Examiner UNITED STATES PATENTS 1,813,723 7/1931 Beaver 27977 1,998,188 4/1935 Dunn 27977 2,639,158 5/1953 Procos 306-28 X 2,682,414 6/1954 Richardson 30628 X 3,177,018 4/1965 Goodwin 285--321 X FOREIGN PATENTS 23,679 8/1883 Germany.

WILLIAM FELDMAN, Primary Examiner, 

1. IN A POWER-DRIVEN KNIFE HAVING TWO CUTTING BLADES IN FACE-TO-FACE RELATION EXTENDING FROM A HANDLE AND MOVABLE IN RELATION THERETO LONGITUDINALLY, TWO OPPOSITE SLIDES MOUNTED IN SAID HANDLE FOR SLIDING MOVEMENT THEREIN ALONG THE LENGTH OF SAID BLADES; SAID BLADES BEING MOUNTED ON SAID SLIDES FOR LONGITUDINAL SLIDING MOVEMENT THEREALONG RESPECTIVELY AND SEPARABLE THEREFROM AND FROM THE HANDLE BY LONGITUDINAL MOVEMENT; EACH OF SAID BLADES HAVING AN OPENING IN THE REGION OF ITS RELATED SLIDE, SPRINGBIASED DETENTS FIXED ON SAID SLIDES RESPECTIVELY AND IN NORMAL POSITIONS THEREOF, RELEASABLY ENGAGING SAID BLADES IN SAID OPENINGS RESPECTIVELY SECURELY HOLDING SAID BLADES ON SAID SLIDES AGAINST RELATIVE LONGITUDINAL MOVEMENT WITH SAID SLIDES RESPECTIVELY, MEANS TO RECIPROCATE SAID SLIDES FOR MOVEMENT IN OPPOSITE DIRECTIONS; BOTH DETENTS REQUIRING A MOVEMENT IN ONE DIRECTION TO SHIFT THEM OUT OF ENGAGEMENT FROM SAID OPENINGS TO RELEASE SAID BLADES FOR REMOVAL FROM SAID SLIDES AND HANDLE AND A SINGLE CAM-CARRYING ELEMENT INCLUDING CAM MEANS MOVABALY MOUNTED LONGITUDINALLY ON THE HANDLE FROM A NORMAL REST POSITION TO AN OPERATIVE POSITION ENGAGING SAID DETENTS AND MOVING SAME IN SAID ONE DIRECTION BY SAID CAM MEANS AND UPON RETURN OF SAID ELEMENT TO ITS NORMAL REST POSITION, ALLOWING SAID DETENTS TO RETURN TO BLADE-ENGAGEMENT POSITION. 